Multiple rotary toothbrush with lip guard



Oct. 20, 1953 n. P. GRovER MULTIPLE RQTARY TooTHBRUsH WITH LIP GUARD Filed sept. so, 194e 2 Sheet'S-#Sheet 1 ,Invenz PonaZ Grover SYN* Mmmm Oct. 20, 1953 D. P. GRovER MULTIPLE ROTARY Too'rRBRusR WITH LIP GUARD Filed Sept, 50, 1946 2 Sheets-Sheet 2 fm2/'5772227' onald R rover wf. CO'I'TWYS Patented Cet. 20, 1953 UNITED STATES PATENT OFFICE MULTIPLE ROTARY TOOTHBRUSH WITH LIP GUARD 7 Claims.

This invention relates in general to rotary toothbrushes and in particular to a type of rotary toothbrush adapted for personal use, as distinguished from those commonly used by dentists.

Various forms of rotary or mechanical toothbrushes have been developed heretofore, but have found very little favor with the public in general. One of the disadvantages of the early type of rotary toothbrush was the absence of any shield partially surrounding the brush element, thus causing some of the toothpaste on the brush to be thrown oif and splattered about during the rotation of the brush and permitting the brush to contact the soft inner portions of the mouth causing irritation thereof.

A later development introduced a shield which extended lengthwise of and partially surrounded the rotating brush element to prevent such splatteringy and mouth irritation. However, actual usage of this type of brush proved unsatisfactory because of the tendency of the lip of the user to be drawn inwardly by the bristles of the brush and between the bristles and the edge of the shield when the brush was placed against the teeth, causing laceration and irritation.

All of these earlier toothbrushes contained but a single brush element and since it is considered as important by dentists that the proper way to brush teeth is away from the gums, it'has been necessary to provide some reversing mechanism in orderto reverse the direction of rotation of the single brush element when cleaning upper and lower teeth. The terminology referring to cleaning or brushing the teeth away from the gums, as used herein, is intended to convey the meaning that the brushing begins on or close to the gums and moves away from the gums toward the biting surface of the teeth.

I have been able to overcome the disadvantages of these earlier types of rotary tooth"- brushes in my present invention, the principal object of which is to provide an electrically driven rotary toothbrush having a plurality of brush elements whereby the teeth of a user may be placed therebetween and thus simultaneously brush and clean the front and back sides thereof.

Another object of the invention is to provide a rotary toothbrush wherein at least two brush elements are provided to receive the teeth of a user therebetween' and to rotate these brush elements toward each other in opposite directions to insure simultaneous cleaning of the front and rear sides of the teeth away from the gums.

A further and more specific object of the invention is to provide a rotary toothbrush having va pairy of brush elements one of which has a surface of convex configuration and thev other of which has a surface of concave configuration whereby the space between the brush elements iscurved similar to the curvature of the upper andlower rows of teeth.

Still another object is to provide a rotary toothbrush having a plurality of rotatable brush elements wherein novel lip guards areelocated adjacent to one or both sides of each brush element to prevent the lip of a user from being drawn inwardly against the bristles of the brush.

A still further object is to provide novel driving means for simultaneously driving the brush elements in opposite directions.

Still another object is to provide a rotary toothbrush wherein, if desired, one or more of the brush elements thereof may be adapted to reciprocate longitudinally during the rotation thereof.

A still further and more specific object of the invention is to provide a rotary toothbrush having twopairs of brush elements mounted for simultaneous or alternate or intermittent rotation whereby the upper and lower teeth of a user maybe simultaneously cleaned. f

Other objects and advantages of the invention will become apparent upon a reading of the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a fragmentary longitudinal vertical section throughr the shank or head portion of one form of the invention;

Fig. 2 is a vertical transverse section taken substantially alongl the plane of line 2-2 of Fig. 1 with one of the brush supporting parts in inoperative position;

Fig. 3 is a fragmentary plan view of the invention as shownin Fig. 1;

Fig. 4 is a plan view similar to Fig. 3 but showing a modified form of the brush elements;

Fig. 5is a fragmentary perspective View of a modified form of driving means for the brush elements;

Fig. 6 is a view similar toFi'g. 5 but showing a further modification of the brush driving means;

Fig. '7 is a view similar to Fig. 6 showinga still further modied form of driving means;

Fig. 8 is a fragmentary perspective view of one end of a brush element showing the manner in which the longitudinal reciprocation thereof is obtained;

Fig. 9v is a fragmentary plan view similar to Fig. 4 wherein two pairs of brush elements are used;

Fig. l0 is a longitudinal vertical section taken substantially along the plane of line IIJ-40 of Fig. 9;' and Fig; 11` is a vertical transverse section taken substantially'along the plane of line ll-ll of 3 Fig. 9 with one of the brush elements partly removed.

Briefly described, the invention herein consists primarily of an improvement over rotary toothbrushes heretofore known in the provision of a plurality of brush elements mounted for simultaneous, alternate, or intermittent rotation to thereby clean both the front and rear sides of the teeth of a user at the same time. While the brush elements of the present invention are illustrated as extending at substantially right angles to the handle or shank of the toothbrush, it will be evident that they may be parallel to the handle portion, as shown, for example, in my cci-pending application filed October 10, 1946, and bearing Serial No. 702,535, or they may be disposed at any other angle found to be convenient. The handle portion is provided in such form so that a rotatable shaft can be mounted therein. In this form of the invention the brush elements extend transversely of the driving shaft and are provided with any suitable mechanism for being driven simultaneously.

I also provide a form of lip guard to be located longitudinally, spirally or transversely of each of the brush elements. The lip guard may take any one of numerous forms such as those disclosed, for example, in my co-pending applications: Ser. No. 691,273, filed August 17, 1946; Ser. No. 691,979, led August 2l, 1946; and Ser. No. 692,270, filed August 22, 1946, all issued December 5, 1950, as patents numbered 2,533,106; 2,533,107; 2,533,108, respectively.

Referring now more particularly to the drawings and especially to that form of the invention shown in Figs. l, 2 and 3, the handle portion I may assume any desired form, but should be of a size which may be conveniently held in the hand and should also be formed of a plastic or other similar non-conducting material. The handle portion or shank I illustrated in Fig. 1 has an elongated opening 2 therethrough adapted to receive an elongated bearing member 3 to rotatably support the drive shaft 4. The means for driving the shaft 4 is not important to the functioning of the device as far as the present invention is concerned and such driving means may include an electric motor embodied as a part of the handle portion or the shaft may be driven from an external source by means of a exible shaft. It is necessary, however, that some suitable driving means be provided for rotating the shaft 4 and thus driving the brush elements simultaneously as hereinafter pointed out.

The shank I may be integral with that part of the handle actually grasped by the user, in which event the term handle portion will include the part illustrated in the various figures. On the other hand, if the shank I is detachable from the actual handle portion, as it may easily be, then the term handle portion as used herein, is intended to include such shank.

The handle portion terminates at its outer end in an up-turned portion 5 extending transversely of the main portion of the handle which is gripped by the hand of a user, and has spaced therefrom and parallel thereto a similar upturned portion 6 to thereby form a shield. The front and rear up-turned portions 5 and 6 are connected by sides 1 and 8, and a central transversely extending partition 9 divides the end of the handle into two transversely extending receptacles I0 and II. The receptacle ID is adapted to receive one of the brush elements I2 while rio 4 the other receptacle II receives the brush element I3.

These brush elements are provided with spindies I4 and I5, each of which has an axially extending opening in each end thereof to receive the yieldable supporting ends I1 of a spring support I3. One of the supporting ends l1 is shown retracted for removal of the brush in Fig. 2. This support I8 may be secured in any desired manner to the end of the handle portion and is preferably formed of a yieldable material to facilitate the removal of the brush element for cleaning and replacement purposes. In the form shown, the support I8 is embedded in the base of the receptacles ID and II and each side 1 and 8 is provided with an opening I9 adjacent each end of each brush element to enable the ends of the support I8 to be moved outwardly, thus disengaging its ends from a spindle for removing the brush element.

t will be obvious that any suitable driving means between the shaft 4 and the spindles I4 and I5 of the brush elements may be utilized to rotate the brush elements simultaneously. One form which such driving means may take is to provide threaded or worm sections 20 and 2| in the shaft 4. At the location of each worm section, the bearing 3 may be provided with upwardly extending spaced supports 22 between which a worm gear 23 may be rotatably mounted on a pin or shaft 24. The worm gear 23 in each case will be in mesh with its corresponding worm section on the shaft 4 at one side thereof and will be in contact with a suitable gear or other form of wheel 25 located centrally of each spindle so that a rotation of the shaft 4 will drive the worm gears 23 and the brush elements I2 and I3 through contact with the gear or wheel 25. It will be evident that if it is desired to rotate the brush elements simultaneously in opposite directions, the threads of the worm sections 29 and 2I may be extended in opposite directions as shown. If it is desired to drive the brush elements in the same direction, then these worm sections may be made accordingly.

As explained in my above referred to co-pending applications, it is highly desirable for the comfort of the user during cleaning of the teeth that lip guards be provided to prevent the lip from being drawn inwardly by the bristles of the brush between the brush element and the shield causing irritation and lacerations. r)These lip guards may take any one of a number of forms and for purposes of illustration I have shown the central dividing partition 9 as beinev provided with upwardly and inwardly extending teeth 26 along each edge thereof. It is, of course, necessary that these lip guards be located along the edge of the brush element which moves downwardly as the device is positioned for cleaning the upper teeth. Thus, when the brushes are adapted to rotate in opposite directions toward each other as shown in Fig. l, the proper position of the lip guards 26 will be as shown in Fig. 3. If for any reason, however, it is desired to rotate the brush elements in the same direction, then one of the lip guards may be placed on the opposite side of the brush from that shown in Fig. 3.

It will be obvious that when two simiiar brush elements are located and rotated in the manner shown and described above, it will be an easy matter for the user to place the end of the toothbrush within the mouth so that the teeth will be received between the brush elements. When the brushes are then rotated toward each other, simultaneous cleaning of the front and back of the teethlwill take place and the brushing wil-l be in accordance with the best practices recommended b-ydentists, which is away from the gums. The invention thus not only saves time, but ob'- viates any necessity for a reversingmechanism to reverse the rotation of the brushes.. The brush elements can be rotated at all times inthe same direction opposite each other withoutreversing to obtain a proper cleaningofthe teeth. This is likewiseA true when the device is inverted for cleaning the lower teeth, wherein the rotation of the brush elements-will be such as'fto brush the teeth away from the gums.

Fig; 4 shows a modied'form' of the shape` of the brush elements. In this form, the construction of all of the elements are identical with those described above with the exceptionthat the dividing partition 9c is curved instead of extending in a-straight line between'the sides'l and 8. The curvature of this partition will'be substantially the same asthe space between the two brush elements which 4receivesthe teeth of a user for cleaning. Such a spacev is providedby forming the surface of one of the brush elements I3aas concave and the surface of the other brush element |20. as convex; The lipguards 26 may be the same orany other desiredvform. but may be-curved in accordancewith the curvature of the surface of the brush elements. This form of the invention is advantageous in that the bristles of the brushv elements may contact a greater tooth surface when heldin one position than may be `had when the space is straightlike that shownin Fig; 3.

Figs. 5, 6 and 'I disclosemodied'forms of driving'means between the shaft and brush elements. In Fig. 5 the wormsections have been omitted from the shaft 4', and the spindles Ma and I5a. are provided with centrally located annular groovesl which areadapted to receive a driving belt or band'Z'I. By'placinga'proper twist to the belts 21, the spindlesY may be driven in lOpps-- site directions as shown in Fig. 5, or if desired, they may be easily placed to drive the brushes in the same direction.

In the form shown in Fig. 6, the shaftd is provided with a single worm section 23 adapted to be contacted' by aworm gear23 located on a suitably mounted shaft 3Q between the two spindles 3! and 32. One end of each spindleisprovidedwith a pulley or annular groove 33 iadapted to receive a driving belt or band 34 whichpasses'around: a similar pulley or annular groove 35 ateach end ofthe central spindle 30. Rotation oftheshaft 4 will rotate the shaft 30 through the wormv and ar worm gear arrangement. and: will drive the spindles 3i `and 32 in opposite-directions byproperly twisting the belts 34. This form of theinvention is advantageous inithatA the bristles of ther brush elements may be continuous along: the length of the spindles, thusavoiding a space in the center thereof within which a driving means is located'like that shown in Figs. 2 and5.

The modied form shown in' Fig. 7 is similar to that illustrated in Fig. 6 in :providing theshaft 4 with the worm section 2li.v which drives the spindley Si] through the worm gear-'29. Instead-of using small belts 34, however; the end, of.` each brush spindle is provided with a disc 36 adapted to be driven through a friction contact with similar discs 3l on each end of the central spindle 30. Instead of discs, of course,l it willibe clear that gears could be used' if so desired.

.Another featureV ofthe invention embodies a construction which willlongitudinally reciprodles..v lli,- 41; 48 and 49 of the brush elements.

cate '.the brush Velements during rotation thereof; thus impartingy a massaging effect tothe gums while the teeth arebeing cleaned. While the specific means by which this action `may-beaccomplished may be varied, one very simple'arrangement is to provide one end of each-of the spindles I4 and I5 with an axially extendingoffsetportion38; Thisportion isfadapted tocooperate withan inwardly extendingproiection 39 formed integrally with=or 'otherwise suitably'secured to oneof the connecting sides 'I- or 8: In Fig. 3 these projections are shown as being in,- tegral with the side 8f The lengthlof each spins dle` is `such asA to permit a longitudinal sliding movement thereof. between the sides, and-onen! the ends I'I of the yieldable support I8 may be-so formed as to' have a greater tension than'the other end` so as to normally,l urge the spindle toward the opposite side andv thus maintaincontact between the projection 39 and the corresponding end of the spindle. The twol projecttions 38 and`33v will then have :a cammingeffect as the spindle rotates to thus produce a reciprocation ofthe spindles and the brush'elements connected thereto. It will be evident that any other suitable yieldable means can be-utilized forurging the spindle into contact withthepro-y jection 3S, such as coiledor leaf springs, without in any way departing from ythe spirit ofthe in,- vention.

Referring now to the form of the invention disclosed in Figs. 9, l0 and 1l, I-have utilized four brush elements instead of the two described above. The four brush relements arelocated in pairs, one above the other, so that a` simultaneous cleaning of the upper and rlowerv teeth may takev place. The shaft` 4 may be similar except that its outer end. will have both upwardlyand downwardly extending end portions 40'and4l, spaced inwardly from which are similar ends 42 and 43. The sides 44 and 45 extend .on both sides ofthe handle inv order to supportthe `four spin- If the driving mechanism to be usedislike that shown in Fig. l, it may be vduplicated .on the lower side byproviding similar worm gears50 and` 5I adapted to be in mesh with the underside of the worm sections and with suitable gear or Wheel means on the spindles 48 and49. The brush elements may be formed either like those in Fig. 3 or similar to thosev in Fig. 4, or they may take any otherl suitable shape as long asthe cleaning properties thereof are not impaired;

The-supporting means for the spindles may be similar except these'yieldablemeans as indicated by the numerals 52 and 53 will preferably extend inwardly toward each other at the center thereof and then bereturn bent as indicated by the numerals 54 and 55.4 to provide duplicate arrangements `at the top v and bottom. When it is desired to remove one of the brush elements, this type ofsupporting meansmay have` one end thereof removedandthe brush element may be 'lifted out in the manner shown in Fig. 11. This is, of course, true with yall-forms of the invention when this type .of supportingmeans is used.

From the foregoing description it will be evident that Il have provided a novel improvement in the art of rotary toothbrushes wherein a plurality of rotatable brush elements are utilized for the simultaneous cleaning of the front and back of the teeth vas `Well as for the simultaneous cleaning of the upper and lower teeth. Novel driving means have been provided. for rotating the brushes: in pairs in opposite directions so that the teeth may be properly cleaned by moving the brushes in a brushing motion away from the gums. The feature of reciprocating the brushes during cleaning for purposes of massaging the gums is a novel improvement which aids in more thorough cleaning and the obtaining of healthier teeth and gums.

It may be clear that the invention may take other specific forms than those disclosed herein such as the shape of the brushes, the driving means, the reciprocating means, and the removability of the brush elements without departing from the spirit of the invention or sacrificing any of the attendant advantages thereof, provided, however, that such changes fall within the scope of the claims appended hereto.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. A rotary toothbrush of the character described, comprising a, handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said brush supporting means in substantially parallel and spaced relation to receive the teeth of a user therebetween, a lip guard extending longitudinally of and between said brush elements and including a plurality of teeth spaced apart along the length of said brush elements, and means for simultaneously rotating said brush elements toward each other.

2. A rotary toothbrush of the character described comprising a handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said brush supporting means and extending transversely thereof in substantially parallel and spaced relation to receive the teeth of a user therebetween, a lip guard extending longitudinally of and between said brush elements and including a plurality of teeth spaced apart along the length of said brush elements, and means for simultaneously rotating said brush elements toward each other.

3. A rotary toothbrush of the character described, comprising a handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said supporting means in substantially parallel and spaced relation to receive the teeth of a user therebetween, a lip guard extending longitudinally of and between said brush elements and including a plurality of relatively thin wall members spaced apart along the length of said brush elements and extending outwardly from the handle therebetween to prevent the lip of a user from being drawn inwardly between said brush elements, and means for rotating said brush elements simultaneously toward each other.

4. A rotary toothbrush of the character described, comprising a handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said supporting means and extending transversely thereof in substantially parallel and spaced relation to receive the teeth of a user therebetween, a lip guard extending longitudinally of and between said brush elements and including a plurality of relatively Vthin wall members spaced apart along the length of said brush elements and extending outwardly from the handle thereby to prevent the lip of a user from being drawn inwardly between said brush Il U elements, and means for rotating said brush elements simultaneously toward each other.

5. A rotary toothbrush of the character described, comprising a handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said supporting means in substantially parallel and spaced relation to receive the teeth of a user therebetween, a partition extending longitudinally of and between said brush elements, a lip guard including a plurality of teeth spaced apart along the length of said partition and positioned along each edge thereof, and means for simultaneously rotating said brush elements toward each other.

6. A rotary toothbrush of the character described, comprising a handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said supporting means and extending transversely thereof in substantially parallel and spaced relation to receive the teeth of a user therebetween, a partition extending longitudinally of and between said brush elements, a lip guard including a plurality of teeth spaced apart along the length of said partition and positioned along each edge thereof, and means for simultaneously rotating said brush elements toward each other.

7. A rotary toothbrush of the character described, comprising a handle portion, brush supporting means on said handle portion, a pair of elongated brush elements rotatably mounted on said brush supporting means in substantially parallel and spaced relation to receive the teeth of a user therebetween, a lip guard extending longitudinally of and between said brush elements and including a plurality of members spaced apart along the length of said brush elements and extending between the bristles thereon, and means for simultaneously rotating said brush elements toward each other.

DONALD P. GROVER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 474,345 Johansson May 3, 1892 952,592 Villani Mar. 22, 1910 1,007,888 Parker Nov. 7, 1911 1,254,532 Paul Jan. 22, 1918 1,430,967 Fendrich Oct. 3, 1922 1,529,691 Davis Mar. 17, 1925 1,555,522 Shapiro zSept. 29, 1925 1,577,751 Paschall Mar. 23, 1926 1,578,495 Zave Mar. 30, 1926 1,795,098 Scadding Mar. 3, 1931 1,822,631 Roig Sept. 8, 1931 1,901,503 Fessenden Mar. 14, 1933 1,927,566 Hawk Sept. 19, 1933 2,044,344 Bagnall June 16, 1936 2,052,656 Prien Sept. l, 1936 2,215,031 Elmore Sept. 17, 1940 2,281,131 Wright Apr. 28, 1942 2,285,865 Lowe et al June 9, 1942 2,435,421 Blair Feb. 3, 1948 FOREIGN PATENTS Number Country Date 327,553 Italy July 16, 1935 442,749 Great Britain Feb. 14, 1936 555,259 France Mar. 19, 1923 676,771 France Nov. 29, 1929 

